1. Field of the Invention
The present invention relates to a method for assembling a testing equipment for a semiconductor substrate.
2. Description of the Related Art
A semiconductor substrate, such as a silicon wafer, is tested by a testing equipment prior to a dicing process regarding a circuit pattern formed in the respective area thereof. Such a testing equipment is provided with a probe head unit movable to each of the areas, having probe pins to be in contact with the respective circuit pattern for delivering or receiving test signals thereto or therefrom as disclosed, for example, in Japanese Patent Application Laid-open No. 2000-321303.
As shown in FIG. 20, the probe head unit includes a reinforcement frame member 2 for reinforcing the rigidity of a printed wiring board 6 described later, a reinforcement frame member 4 disposed inside of the reinforcement frame member 2 for reinforcing the rigidity of the printed wiring board 6 in cooperation with the reinforcement frame member 2, the printed wiring board 6 disposed on one side surfaces of the reinforcement frame members 2 and 4 as a test board for delivering test signals or others to the respective circuit patterns of a semiconductor substrate to be tested, a pitch-changing substrate 8 for electrically connecting the printed wiring board 6 to a contact block 12 described later, and a contact block 12 disposed on the pitch-changing substrate 8, having a plurality of probe pins 14ai (i=1 to n, n is a positive integer) for electrically connecting the pitch-changing substrate 8 to the respective circuit patterns of the semiconductor substrate (not shown) to be tested, and a cover member 10 for fixing the contact block 12 to the reinforcement frame members 2 and 4 via the printed wiring board 6 while bringing the contact block 12 into contact the pitch-changing substrate 8.
In FIG. 20, the reinforcement frame member 2 has an opening 2a at a center thereof. The reinforcement frame member 4 is inserted into the opening 2a at a predetermined gap between both the members. A plurality of female-screw holes are formed on the periphery of the opening 2a along the circumference thereof, and machine screws Ba for fixing the cover member 10 are threaded therein and threaded-engagement therewith. The reinforcement frame member 4 has a plurality of female-screw holes along the circumference thereof. Machine screws Bb are threaded into each female-screw holes and threaded-engagement therewith so that the contact block 12 is fixed to the printed wiring board 6 via the pitch-changing substrate 8.
In a central region of the printed wiring board 6, there is a group of electrodes formed in correspondence to connection terminals of the pitch-changing substrate 8 to be electrically connected thereto. The electrode group is connected via the probe head unit to a tester for testing electrical characteristics of circuit patterns in the semiconductor substrate. The printed wiring board 6 also has through-holes through which pass the above-mentioned machine screws Ba and Bb respectively.
In a central region of the pitch-changing substrate 8, there is formed a group of electrodes electrically connected to one ends of the probe pins 14ai of the contact block 12. The electrodes in the group are formed in correspondence to a relatively narrow pitch of the probe pins 14ai. Also, the electrode group are connected, via a predetermined conductive patterns, to connection terminals formed on a rear surface of the above-mentioned printed wiring board 6 in correspondence to the group of the electrodes. A pitch of the connection terminal group is larger than the pitch of the electrode group. The pitch-changing substrate 8 has holes through which pass the machine screws Bb. The pitch-changing substrate 8 is positioned to the printed wiring board 6 by inserting the machine screws Bb coaxially into the holes in the pitch-changing substrate 8 and the printed wiring board 6.
The contact block 12 has a plurality of probe pins 14ai in correspondence to the group of electrodes in the pitch-changing substrate 8. There are through-holes through which pass the machine screws Bb on the outer peripheral edge of the contact block 12. A plurality of recesses are provided along the circumferential direction in the contact block 12 between the plurality of probe pins 14ai and the through-holes through which pass the machine screws Bb, the recesses for accommodating one ends of coil springs CS for biasing the contact block 12 toward the pitch-changing substrate 8. The other ends of the coil springs CS are accommodated in recesses formed in the inner circumference of the cover member 10.
The outer periphery of the contact block 12 is engaged with an inner periphery portion 10b described later of the cover member 10 at a predetermined gap therefrom. A central convex of the contact block 12 is engaged with the inner circumferential portion defining a larger opening 10a of the cover member 10 at a predetermined gap therefrom.
After the passable positioning of the probe pins 14ai in the contact block 12 to the electrode group of the pitch-changing substrate 8 has been finished by inserting the machine screws Bb into the through-holes in the contact block 12 and the pitch-changing substrate 8, the current is actually sent between the probe pins 14ai in the contact block 12 and the electrode group in the pitch-changing substrate 8. When the conductive state has not been confirmed thereby, the mutual positioning is adjusted again.
The cover member 10 has the opening 10a at a central region thereof and also has a larger opening 10b to be engaged with the outer circumference of the contact block 12. The smaller opening 10a communicates with the larger opening 10b. Through-holes into which are inserted the machine screws Ba, Bb are formed around the opening 10a in the circumferential direction.
In such a structure, upon assembling the probe head unit, first the reinforcement frame member 4 is disposed in the opening 2a of the reinforcement frame member 2, then the printed wiring board 6 is laid on the reinforcement frame member 2, after which the pitch-changing substrate 8 and the contact block 12 are laid on the printed wiring board 6. Subsequently, the cover member 10 is laid on the contact block 12, and thereafter, the machine screws Ba, Bb are inserted into the respective holes and screwed into the female-screw holes in the reinforcement frame members 2 and 4. Thus, the temporary assembly of the probe head unit is finished. Then, it is confirmed whether or not the positioning of the probe pins 14ai in the contact block 12 relative to the electrode group in the pitch-changing substrate 8 as well as that of the group of connection terminals in the pitch-changing substrate 8 relative to the terminal group in the printed wiring board 6 are proper, by the conductive state as a result of supplying predetermined signals to the printed wiring board 6, and if it is confirmed that the positioning is proper, the machine screws Ba, Bb are more tightly retightened to a complete degree.